*{
    margin: 0;
}
#underDiv{
    position: absolute;
    width: 700px;
    height: 250px;
    bottom: 0;
    display: flex;
    justify-content: center;
    align-items: center;
    text-align: center;
}

body>div{
    width: 700px;
    height: 500px;
    background-image: url("../../img/catBack7.webp");
    background-size:100%;
    font-size:18px;
    font-weight: bold;
}
nav,foot{
    width: 500px;
    height: 30px;
}
#delDiv{
    background-color: skyblue;
    border: 1px solid #000;
    width: 500px;
    height: 300px;
    text-align: center;
    line-height: 50px;
    position: absolute;
    left: 100px;
    top: 100px;
    visibility: hidden;
}

#addDiv{
    border: 1px solid #000;
    background-color: skyblue;
    width: 500px;
    height: 300px;
    line-height: 50px;
    text-align: center;
    position: absolute;
    top: 100px;
    left: 100px;
    visibility: hidden;
}